Although considerable progress has been made in the management of the physiological alterations associated with severe thermal injury, pulmonary problems and loss of resistance to infection resulting in overwhelming gram-negative septicemia and death have continued to consitute a significant threat to the survival of the severely burned patient. The proposed program of investigations outlined in this application is based upon the concept that a significant component of these complications is related to alterations in cellular and humoral mechanisms of immunological responsiveness. It is proposed to identify and delineate those immunological parameters which are most affected by thermal injury in order to provide a better understanding of the pathogenesis, treatment and prevention of the above listed complications of burn disease. Particular attention will be given to: a) in vivo and in vitro cellular and humoral studies of immunological competence in burned animals; b) studies of the role of microemboli of platelets and fibrin as an etiological factor of post-burn anoxia; c) further investigations of autoimmune sequelae of thermal injury in experimental animals.